Circuit configurations of this kind are described in German Patent No. 32 46 329. When an upper voltage limit is reached, the voltage is short-circuited in such a way that the current of the current-transforming device no longer flows into the charging capacitor. In this switching operation, electromagnetic interference fields arise which corrupt the measurement current, thereby causing erroneous tripping.
European Patent No. 0 130 254 describes relevant tripping device with two capacitors, which are to be charged by the current-transforming device for the operation of this device.